Universal Battery Monitor

Bluetooth

The battery has a built-in BMS that broadcasts over Bluetooth Low Energy. Use the monitor above to connect from your phone or laptop — no separate app required, and it works offline once loaded.

You can read state of charge, pack voltage, per-cell voltages, charge/discharge current, temperature, cycle count, and any active BMS protections (over-voltage, under-voltage, over-temp, short-circuit). Only one client can be connected at a time.

If the battery does not appear: make sure it is not fully asleep (apply a small load or briefly connect a charger to wake it), stand within a few meters, and close any other BMS client that may already be holding the connection.

Heat function

LiFePO4 cells must not be charged below 0 °C / 32 °F — doing so plates lithium on the anode and permanently damages the pack. The Heat function exists to prevent this.

It is automatic. When the internal temperature sensor reads below roughly 5 °C (41 °F) and the BMS detects an incoming charge current, it diverts that current to heating pads bonded to the cells instead of charging them. Once the cells warm above about 5 °C, the BMS releases the current to normal charging.

• You don't need to push a button. Heat will not run from the battery's own stored energy — it only activates when a charger, alternator, or solar controller is connected and producing current.
• Pre-heating can take 30 minutes to a few hours depending on how cold it is and how much current your charger supplies. During this time the state of charge will not go up. This is normal.
• Discharge below 0 °C is generally allowed (down to roughly −20 °C) — only charging is gated.
• If you see a "low temp" or "charging protected" alert in the Bluetooth app while plugged in to a charger, the heater is doing its job. Leave it connected.